EP2835163A1 - Filter bag for a vacuum cleaner and a method for determining a surface of a vacuum cleaner dust bag which is directly impacted by the air flow - Google Patents

Abstract

The present invention relates to a filter bag for a vacuum cleaner, which is formed from a filter material comprising at least three filter material layers. In the case of the filter material layers, at least one layer is a scrim and at least one layer is a nonwoven layer which comprises unconnected staple fibers and / or unconnected filaments.

Description

The present invention relates to a filter bag for a vacuum cleaner, which is formed from a filter material comprising at least three filter material layers. In the case of the filter material layers, at least one layer is a scrim and at least one layer is a nonwoven layer which comprises unconnected staple fibers and / or unconnected filaments. The filter bag additionally comprises an inlet opening through which air can flow into the filter bag. The filter bag according to the present invention is characterized in that in an area of the filter bag, in particular where the air flow entering through the inlet opening into the vacuum cleaner filter bag impinges directly on the filter material at least one connection point is present, in which the at least one nonwoven fabric layer at least one of the at least two further layers is connected so that a permanent fixation of the staple fibers and / or filaments of the nonwoven layer with at least one of the at least two further layers is ensured is. This area makes up a maximum of 20% of the total permeable surface of the filter bag. The pressing surface portion of this joint, based on the area is between 0.1 and 40%. In the other areas or areas of the filter bag as well as connecting points of the unconnected fibers or filaments may be present, but these compounds are optional there. In any case, the pressing surface portion of the joints in the remaining areas is thus less than in the area or areas.

Vacuum cleaner filter bags with multilayer filter materials, in which, for example, a layer of the filter materials unconnected nonwoven fabric layers are known from the prior art, for example EP 1 795 247 and the EP 1960 084 known. In this case, it has been found that the vacuum cleaner filter bags have the better dust storage capability, the less welding points are available for connecting the layers of the filter material of the vacuum cleaner filter bag.

A disadvantage of such filter bags with very few welds, however, is that the filter material has a lower mechanical stability and thus can be damaged at the high inlet velocities of the air flow in the vacuum cleaner filter bag. In particular in the impact area of the air stream or the particles transported with the air flow onto the filter material, the unconnected fibers of the nonwoven layer, for example the loose staple fibers are displaced, thereby exposing the underlying filter material layer, for example the fine filter layer or a scrim.

Due to the missing pre-filter function, this filter material then clogs quickly, often it is also destroyed by the air or particle flow.

So far, such a problem has been solved by the prior art in that impact protection devices, such as reinforcing inserts were mounted on the inside of the vacuum cleaner filter bag. This was a mostly large-scale bonding or welding a relatively rigid and mechanically stable impact protection with the inside of the area in which the air flow directly to the wall of the Filter material hits made. In this case, for example, perforated or unperforated films, nonwovens or pieces of paper are glued or welded onto this area. For example, this describes EP 1 415 699 various variants of such applied to a patch protection pieces. In the EP 2 510 859 a piece of material with a corresponding impact protection function is described. The DE 20 2004 019 344 describes a reinforcing layer of foam or nonwoven plastic fiber material opposite the inlet opening. The DE 20 2009 002 970 discloses a similar baffle with a baffle.

However, this has the disadvantage that in the area of the impact protection device, the air permeability of the filter material is no longer present, so that an increased pressure drop is given in the vacuum cleaner filter bag. As a result, the storage capacity of the filter material is also greatly reduced, so that overall the performance of the filter bag is noticeably reduced. In addition, an uneven distribution of the incoming dust particles in the filter bag, which affects the service life sustainable.

Based on this, it is an object of the present invention to provide a vacuum cleaner filter bag having a high dust storage capacity, a long service life and a low pressure loss. In addition, it is an object of the present invention to specify a method with which the impact area of an air stream entering the vacuum cleaner filter bag (= directly flowed area or area) can be precisely determined and determined on the filter material.

This object is achieved with respect to a filter bag with the features of claim 1, with respect to a method for determining the area directly flowed by the air flow entering through the inlet opening into the interior of the filter bag or, in the case where there are several areas, the areas with the Characteristics of claim 21 solved. The dependent claims are advantageous developments.

According to the present invention there is thus provided a filter bag for a vacuum cleaner comprising a bag of a filter material comprising at least three layers of filter material, at least one layer of which is a scrim and at least one layer is a nonwoven layer containing staple fibers and / or filaments, and an inlet opening in the bag.

According to the invention, it is provided that the complete flow-through region of the filter material is subdivided into two qualitatively different regions. In one area or a plurality of areas, taken together or make up a maximum of 20% of the permeable surface of the filter bag or make up and possibly an additional area that immediately surrounds the aforementioned area, or in the event that several Areas are present, several additional areas, each directly surrounding the area X, there are one or more connection points of the filter material. In this case, the at least one nonwoven fabric layer is connected at least to one of the at least two layers Scrim at the connection point or in the event that a plurality of connection points are present. This ensures that, during operation of the filter bag, a permanent fixation of the staple fibers and / or filaments of the nonwoven layer with the at least one further of the at least two further layers Scrim is ensured. The remaining area or other surfaces thus make up at least 80% of the permeable surface of the filter bag. According to the invention, it is now provided that the pressing surface portion of the connection points in the previously defined area or areas, which make up or account for a maximum of 20% of the through-flow surface of the filter bag and possibly additionally in additional areas, which make up a maximum of 80% of the area of the area , from 0.1 to 40% and is greater than in the other areas or areas.

In the remaining areas, the individual filter material layers of the filter bag can also be completely unconnected.

According to the present invention, it is thus provided that only in one region of the vacuum cleaner bag is the nonwoven fabric layer with at least one other Stabilize material layer through compounds, in which area an increased density of the compounds is selected so that the pressing surface portion of the joints in this area and possibly additional, the area surrounding areas is increased.

According to a preferred embodiment, the area or regions is located where an air flow entering the interior of the filter bag through the inlet opening occurs directly on the filter material, which thus constitutes a directly flown area.

The present invention is therefore based on the finding that at least three-ply filter materials containing at least one layer of nonwoven fabric, excellent dust storage capacity, but due to the loose fibers contained in the nonwoven fabric layer, have a reduced mechanical stability. In particular, in the area in which there is a direct impact of the air flow or the dust particles transported with the air flow, mechanical damage, in particular this nonwoven layer, can take place in the course of the vacuum cleaner operation, in that the loose fibers of the nonwoven layer are displaced or blown away by the air stream passing through the filter material become. This leads to the above-mentioned problems, whereby the service life and the separation efficiency of the dust filter bag deteriorates.

In the filter bag according to the present invention, it is now essential that at least the fibrous nonwoven layer, ie the filter layer of the vacuum cleaner filter bag in which loose and unconnected staple fibers or filaments are present, is connected to at least one of the further layers, so that a permanent fixation of the staple fibers resp the filament of the nonwoven layer is ensured with at least one of the further layers. This connection is preferably formed at least in the region or the surface of the filter material, in which an immediate flow with the entering into the filter bag airflow, ie in a region in which the airflow entering the vacuum cleaner filter bag directly and quasi unbraked on the Filter material impinges. This area of the vacuum cleaner filter bag is the area of highest mechanical stress represents.

It has surprisingly been found that it is completely sufficient for filter bags with a loose fiber layer (nonwoven layer), for mechanical stabilization of the vacuum cleaner filter bag, e.g. only to stabilize the most vulnerable areas by joints, such as welding. As a result, an effective mechanical fixation of the loose fibers is achieved, so that they can no longer be displaced by the incoming air flow and remain at the intended location even with greater mechanical stress due to the air flow. As a result, a vacuum cleaner filter bag is realized, which has an excellent service life with very high dust storage capacity. At the same time, it is therefore possible to dispense with the impact protection devices known from the prior art, so that the problem of high pressure loss in the vacuum cleaner filter bag can also be avoided. By omitting the impact protection devices, the production of the vacuum cleaner bag is also simplified and cheaper.

Preferably, therefore, the region or, in the presence of a plurality of regions, the regions in which or in which the air flow impinges directly and in which mechanical damage can thus occur is or will first be determined. In these areas, according to the invention, the loose fibers are fixed by connecting points, in which the loose fibers of the nonwoven layer are connected to at least one of the further layers. As a result, the mechanical damage is prevented by air flow.

The method for the determination of the directly flowed-on area or in the presence of a plurality of directly impacted areas is described in detail below and also corresponds to a concept according to the invention.

According to the present invention, it is now provided that a higher density of connection points is provided in the above-defined region or regions, in particular in the regions or surfaces of the vacuum cleaner filter bag that are directly flown, than in the remaining regions of the vacuum cleaner filter bag, ie the pressing surface portion (this is the proportion which makes up the area of the connection points, based on the directly flowed surface) is higher than in the other areas of the vacuum cleaner filter bag. It has been recognized according to the invention that the pressing surface portion in this region, preferably in the directly flowed-on surface or in the directly flowed surfaces of 0.1 to 40%, is sufficient to completely prevent mechanical damage to the fiber fleece layer.

Further improvement and increase in mechanical stability can be achieved by not only in this area, e.g. In the directly flowed area or the directly flowed areas connecting points are provided, but also in areas that are directly adjacent to this area and this.

In a preferred embodiment, the pressing surface portion of the one or more joints in the above-defined area, or the areas, in particular in the directly flowed area or in each of the directly flowed areas and possibly the additional area or the additional areas of 0, 25 to 20%, more preferably from 0.5 to 10%.

The area of the additional area which adjoins the area or areas defined above is preferably 10 to 80%, more preferably 20 to 70%, particularly preferably 30 to 60% of the area of the area defined at the outset.

The additional area is advantageously concentric around the area defined above, e.g. arranged directly to the flowed area and z. B. be formed circular or oval-shaped or be modeled on the geometric shape of the directly impinged area.

According to a further preferred embodiment, in the remaining areas, the at least one nonwoven layer is connected to at least one of the at least two further layers Scrim, with the proviso that, based on the total flow-through surface of the filter bag in the other surfaces of the pressing surface portion of one or the sum of the plurality of joints is not more than 5% of the permeable area of the filter bag in the remaining areas and an average of at most 10 joints per 10 cm ² are present.

The filter material of the vacuum cleaner can thus be formed in an analogous manner, as the patent applications EP 1795 247 and EP 1 960 084 underlying. With regard to the filter material that can be used for the filter bag according to the present invention, reference is made in particular to these two European patent applications described above. In particular, with regard to the material definition of a scrim or a nonwoven fabric layer is on the EP 1 795 247 A1 Referenced. All definitions in terms of the terms "nonwoven fabric layer", "nonwoven fabric layer", "staple fiber" and "filaments" are used in an identical manner in the definition of the present invention, as used by the EP 1 795 247 A1 underlie.

In addition to the statements of the prior art, ie the EP 1795 247 and the EP 1 960 084 It can also be given in the present invention, that the individual filter material layers - with the exception of the defined area or areas - are unconnected, ie, for example, are not connected by welding points, so that no welding connection is given between the individual filter material layers, ie it is Alternatively, it is also possible that in the remaining areas the at least one nonwoven layer is unconnected to the further layers Scrim.

According to an advantageous embodiment, in the initially defined region or regions, in particular in the directly flowed-on region or in the directly flown regions and possibly the additional region or regions, the one or more connection points is bar-shaped, cross-shaped, star-shaped, point-shaped , or formed linear and / or circular.

According to a particularly preferred embodiment, in the initially defined region or regions, in particular in the directly streamed Region or in the directly flowed areas and possibly the additional area or the additional areas a plurality of point or bar-shaped connection points present, which are arranged on a plurality of concentric circles.

In the other areas of the filter bag according to the present invention, it is preferred if on average at most 5, preferably at most 2, more preferably at most 1, more preferably at most 0.8, further preferably at most 0.6, in particular at most 0.3 compounds per 10 cm ² are present and / or the pressing surface portion of the compounds in the remaining surfaces is at most 2%, preferably at most 1% of the surface area of the flow-through surface of the filter bag in the remaining areas.

It is advantageous that the scrim has a basis weight of 3 to 50 g / m ² .

Under a scrim according to the present invention, in particular netting, in particular a woven, extruded or fibrilized netting, a perforated film, weldable paper, in particular tea bag paper, as well as any type of nonwoven, especially wet laid, drained or extruded nonwoven understood.

According to the present invention, it is unnecessary for the filter bag to have an impact protection device and / or reinforcing inserts in the initially defined region or regions, in particular in the region or regions directly impacted, and optionally in the additional region or in the additional regions. According to the present invention can thus be completely dispensed with the aforementioned impact protection device. As a result, in particular a high pressure loss at the respective impact protection devices is avoided.

The joints both in the additional areas, as well as in the other areas (if any), in particular by welded joints, preferably ultrasonic welded joints or thermal welds, or by adhesive bonds, or by needling at least the nonwoven fabric layer and at least one Scrimlage respectively.

In particular, it is advantageous if the fiber fleece layer is embedded between two scrim layers and all of these three layers are connected to one another at the connection points. This can, for example, in an advantageous manner by means of an ultrasonic welding connection, for. B. be realized by ultrasonic calendering. This connection technique can be applied both in the directly flowed surface (s), in the additional regions and in the remaining regions of the filter bag.

The aforementioned preferred embodiments for the nature and manufacture of the joints apply to all joints realized in the vacuum cleaner filter bag according to the invention, i. for all junctions that may occur in the directly impinged areas, the additional joined areas that are located around the areas that are directly streamed, but also in the remaining areas of the vacuum cleaner filter bag.

Further advantageously, the filter material comprises e.g. downstream of at least one further filter material layer, e.g. a meltblown layer and / or a spunbonded layer. Preferably, all the filter material layers are connected to one another at the connection points.

Furthermore, it is possible for the inlet opening to have a deflection device, via which the flow direction is changed, the air flow entering the interior of the filter bag. With such a deflection device, for example, a change in the flow direction into the interior of the filter bag by several 10 °, for example up to 90 ° is possible. It is also possible that a closure flap is attached to the inlet opening. The aforementioned devices can influence the position of the directly flowed area. Thus, in the case where a deflector is attached to the inlet port, the direction of the airflow entering the vacuum cleaner filter bag is changed. In this case, the area directly flowed inside the vacuum cleaner filter bag is of course at the point where the deflected Air flow impinges on the inner wall of the vacuum cleaner filter bag. Thus, the connection of the at least two layers of material of the filter material at the appropriate location to choose.

In addition or as an alternative to the aforementioned embodiments, it is also possible for the filter bag to comprise at least one flow divider which divides the air flow entering through the inlet opening into the interior of the filter bag into at least two partial flows with a different main flow direction. In the event that a flow divider is present, it may be the case that a plurality of directly impinged areas result, which are each flown by a partial flow - resulting from the flow divider. In this case, it is preferable if each sub-stream is assigned an immediately-streamed area and a corresponding compound, i. one or more junctions at the determined locations, i. the directly flowed areas is present. Thus, the filter material has one or more connection points in each directly flowed-on region of a respective partial flow and, if appropriate, additionally in an area which surrounds the respective directly flowed-on region.

However, it may also be possible that corresponding device, as mentioned above, for example deflection devices or flow dividers are introduced at the neck of the vacuum cleaner itself, wherein the nozzle is then introduced via the inlet openings in the vacuum cleaner filter bag. The method according to the invention for the determination of areas directly in a dust filter bag also makes it possible, with suitably designed vacuum nozzles, with which the air is blown into the dust filter bag, to determine those areas or areas which are directly affected by the respective air streams ,

According to a particularly preferred embodiment, it can be provided, for example, that the filter bag is designed as a flat bag or as a gusseted flat bag. In the case of a flat bag two z. B. rectangular filter material layers (each with a total of at least three, for example, five layers) superposed and connected to each other at the edges, For example, welded together. The two filter material layers each represent one side of the filter bag. In a gusseted bag, the filter bag is also formed by two mutually connected layers of filter material, however, the two layers of filter material are wrapped on two opposite sides, whereby an inner fold is formed, which can be everted in the operating state. The first filter material layer has an inlet opening. The second filter material layer has, for example, an area opposite the inlet opening, which preferably represents the area directly in the flow. Here, a plurality of connection points are formed, in which the material layers of the filter material are welded together. This area has an area that makes up a maximum of 20% of the total permeable area of the filter bag. The pressing surface portion of the welds is higher in this area than in the other areas of the filter material.

However, other geometric embodiments of the filter bag are conceivable and also preferred. In the event that the vacuum cleaner filter bag can be formed, for example, as a block bottom or block bottom bag, it can be provided that the filter bag has a rectangular cross section, the filter bag thus has four walls, which are formed from the corresponding filter material. In such a case, it may be provided, for example, that the air stream is blown by the vacuum cleaner itself by means of a nozzle into the vacuum cleaner filter bag, this nozzle may also have a deflection device for the injected air flow. In this case, it is preferred if there is a corresponding connection of the individual material layers of the filter material, as defined above, at least on the side to which the air flow directly occurs (eg, on which a directly impinged surface is present). Filter bags made of nonwoven fabrics, which have shapes that correspond to the classic block or block bottom bags made of filter paper, for example, from DE 20 2009 004 433 U1 and the DE 20 2005 016 309 U1 known. Likewise, a pleated form of the filter bag is conceivable, such filter bags are z. B. in the EP 2 366 319 Are defined. The disclosure of this application also applies to the aforementioned pleated filter bags. For example, this connection may also be on several or all of the sides of the vacuum cleaner filter bag to be available.

As shown above by way of example, the position of the directly impinged area or the directly impinged areas on the respective geometry of a vacuum cleaner filter bag and optionally existing flow dividers or deflectors for flows from, for example, deflection devices also on the corresponding vacuum cleaners or nozzles in the Filter bag are introduced and thus can not be attached to the vacuum cleaner filter bag. The choice of the connected area or the location of the area (s) directly flown in must therefore be determined and determined separately for each type of vacuum cleaner filter bag.

Preferably, the staple fibers of the nonwoven fabric layer have a length between 30 and 250 mm, preferably between 50 to 150 mm.

Exemplary staple fibers are selected from the group consisting of split fibers, electrostatically charged staple fibers, natural fibers, chemical fibers and / or crimp fibers, wherein the crimp fibers preferably have different spatial structures, preferably of zigzag, waves and / or spiral type and / or are selected from the group consisting of mechanically crimped fibers, autocrimp fibers and / or bicomponent fibers.

The surface-related mass of the at least one nonwoven fabric layer is preferably between 10 and 200 g / m ² , in particular between 20 and 100 g / m ² .

Alternatively or additionally, the basis weight of the scrim may be at least 3 g / m ² .

In particular, the filter material comprises at least three filter material layers, wherein a nonwoven fabric layer is arranged between two scrim layers.

Optionally, it is possible that the filter material comprises at least four, preferably at least five filter material layers, wherein in addition to the three said filter material layers at least one further filter material layer, selected from the group consisting of fine filter layers, paper, nonwoven material and / or nanofibers is included. This further filter material layer is preferably arranged downstream of the filter bag.

For example, a corresponding holding plate for a respective type of vacuum cleaner may also be attached to the inlet opening. Particularly preferred holding plates which are suitable for the purposes of the present invention are, for. B. in the European patent application with the application number 11 010 202 called. With regard to possible embodiments of preferred holding plates for the present invention, reference is made to this patent application.

As can be seen from the preceding embodiments, it is particularly necessary to allow the most accurate possible determination of the position of the directly flowed area in order to attach there a reliable connection of the individual layers of material of the filter material can. In this case, the position of the area directly flown depends not only on the geometrical conditions of the vacuum cleaner filter bag, but also on any existing baffles that deflects an incoming air flow into the interior of the vacuum cleaner filter bag in its direction or flow dividers, for example, an incoming air flow into at least two partial streams can divide. If necessary, deflection devices may also be provided on the corresponding vacuum cleaners, for example suitably designed connecting pieces which do not inject the flow straight through the inlet opening of the vacuum cleaner filter bag into the interior of the bag.

• Faservlies aus Stapelfaser
  • ○ Grammatur der Faservlieslage
  • ○ Länge der Stapelfaser
  • ○ Durchmesser der Stapelfaser
  • ○ Geometrie der Stapelfaser (gerade, mit crimp)
  • ○ Material der Filamente
• Faservlies aus Filamenten
  • ○ Grammatur der Faservlieslage
  • ○ Durchmesser der Filamente
  • ○ Geometrie der Filamente (gerade, mit crimp)
  • ○ Material der Filamente

Other influencing factors are, for example, the type of filter material, in particular the nonwoven fabric:

• Nonwoven made of staple fiber
  • ○ Grammage of the non-woven fabric layer
  • ○ length of staple fiber
  • ○ Diameter of the staple fiber
  • ○ geometry of the staple fiber (straight, with crimp)
  • ○ Material of the filaments
• Non-woven fabric of filaments
  • ○ Grammage of the non-woven fabric layer
  • ○ Diameter of the filaments
  • ○ Filament geometry (straight, with crimp)
  • ○ Material of the filaments

• ○ Durchmesser des Stutzens
• ○ Richtung der Einströmung (Bananenstutzen, Rückschlagklappen)
• ○ Einströmende Luftmenge (Motorleistung)
• ○ Beutelgeometrie
• ○ Beutelfaltung / Beutelentfaltung
• ○ Im Beutel vorhandene Strömungsverteiler (Aufteilen und oder Umlenken der Strömung)

Likewise, the manner in which the surface is impinged plays a role, which in particular depends on:

• ○ Diameter of the neck
• ○ Direction of inflow (banana nozzles, check valves)
• ○ inflowing air quantity (engine power)
• ○ bag geometry
• ○ Bag folding / bag unfolding
• ○ Flow distributors in the bag (splitting and / or diverting the flow)

The present invention therefore also provides a method for determining the area or regions of the filter bag directly flown through by an air stream entering through the inlet opening into the interior of a filter bag for a vacuum cleaner, in which a filter bag comprising a filter material comprising at least three filter material layers, of which at least one layer is a scrim and at least one layer of a nonwoven fabric layer containing staple fibers and / or filaments, and an inlet opening mounted in the bag, inserted into a suitable for the filter bag vacuum cleaner and for 5 minutes at the highest possible power setting of the vacuum cleaner air in the Filter bag is sucked through the inlet opening.

Thereafter, the filter bag is removed from the vacuum cleaner and the inside of the filter bag is examined. Those areas which have visually detectable damage are defined here as directly impacted area, or in the presence of several damaged areas as areas directly impacted.

In the determination method according to the invention thus a quasi identical filter bag is used for a vacuum cleaner, as described above according to the invention, with the proviso that the filter material of this filter bag in the directly flowed surface or in the presence of multiple surfaces or surfaces has no connection points. The filter material of this filter bag used for test purposes thus corresponds to the filter material of the vacuum cleaner as described according to the invention in the other areas.

With this filter bag, the above test method is performed, then the bag is opened (eg by removing the circumferential welds) and closed based on the damage occurring on the directly flown surface or surfaces.

Damage can be assumed, for example, if the fiber fleece layer of the filter material is thinned out by the incoming air flow or fibers are blown away from the fiber fleece layer by the air flow at this point. The sites of damage thus correspond to thinned or thickened areas in the filter material. These ranges can be determined visually, or determined, for example, by measuring the average thickness of the filter material before and after the vacuuming of the suction test, as described above. At the points where a deviation from the average thickness of the filter material is observed, a damaged area is assumed. The thickness of the filter material can be determined according to EN ISO 9073-2: 1996.

A preferred embodiment for this provides that in the filter bag used for the determination method according to the invention, the at least one nonwoven fabric layer is connected to at least one of the at least two further layers Scrim, with the proviso that, based on the entire durchströmbare surface of the filter bag, the pressing surface portion of the one or the sum of the plurality of connection points a maximum of 5% of the flow-through surface of the filter bag and an average of at most 10 connection points per 10 cm ² are present, or at least one nonwoven fabric layer with the other layers Scrim is unconnected.

In particular, it is preferable if the vacuum cleaner (if present) is operated without a hose in order to minimize flow losses in order to obtain as unaltered a result as possible.

According to a further preferred variant of the investigation process During the operating time of the vacuum cleaner and small amounts of dust, sand, toner or combinations thereof are sucked into the interior of the vacuum cleaner filter bag. Exemplary amounts thereof are about 5 to 15 g, for example 10 to 12 g. In particular, in the event that toner or a mixture of toner and sand or toner and dust is introduced, the visualization of the damage thereby achieved in the immediate area encountered is improved.

The knowledge gained from the above-described preliminary methods can also be used for producing a vacuum cleaner filter bag according to the invention. For this purpose, first of all, for a respective geometric shape of the vacuum cleaner filter bag in accordance with the above-described method, the point at which the directly impinged surface or, in the case of several directly impinged surfaces, the areas directly impacted are located. At least in these areas and possibly additional areas then at least one or more joints is introduced into the filter material layer of an otherwise geometrically identical vacuum cleaner filter bag to permanently fix there the loose fibers of the fiber batt with at least one other scrim. The pressing surface portion is to choose according to the information of claim 1.

• Figur 1 einen Flachbeutel ohne Verbindungsstellen in der unmittelbar angeströmten Fläche nach Durchführung des Bestimmungsverfahren,
• Figur 2 den prinzipiellen Aufbau des Filtermaterials, das dem Filterbeutel gemäß Figur 1 zugrunde liegt,
• Figur 3 einen Flachfilterbeutel gemäß der vorliegenden Erfindung nach Durchführung des erfindungsgemäßen Testverfahrens,
• Figur 4 ein Detail des Filterbeutels aus Figur 3,
• Figur 5 verschiedene mögliche Geometrien für Verbindungsstellen in der unmittelbar angeströmten Fläche gemäß der vorliegenden Erfindung, sowie
• Figur 6 einen Querschnitt durch ein erfindungsgemäßes Muster von Verbindungsstellen in der unmittelbar angeströmten Fläche.

The present invention will be explained in more detail with reference to the figures attached hereto, but without restricting the invention to the specific parameters shown. Show

• FIG. 1 a flat bag with no connection points in the directly flowed surface after carrying out the determination process,
• FIG. 2 the basic structure of the filter material, the filter bag according to FIG. 1 underlying,
• FIG. 3 a flat filter bag according to the present invention after carrying out the test method according to the invention,
• FIG. 4 a detail of the filter bag FIG. 3 .
• FIG. 5 various possible geometries for joints in the directly flowed surface according to the present invention, as well as
• FIG. 6 a cross section through an inventive pattern of joints in the directly flowed surface.

In FIG. 1 a vacuum cleaner filter bag is shown, with which the method according to the invention for the determination of the directly flowed surface has been carried out. The vacuum cleaner filter bag is a flat bag, which is welded around its edges. In FIG. 1 the cut vacuum cleaner filter bag is shown, while the existing at the edges circumferential weld was cut on three sides, there is only one weld (fold line F) available. The two sides shown in the figure on the left and right thus represent the front and rear of the filter bag. The front has an inlet opening E with a cap K, through which the inlet nozzle of the vacuum cleaner can be inserted into the vacuum cleaner filter bag. In the FIG. 1 shown right side (to the right of the fold line F) thus represents the back of the vacuum cleaner filter bag. In FIG. 1 is a look at the inside of the vacuum cleaner filter bag specified, ie on the upstream side of the filter material. The filter material of in FIG. 1 shown filter bag consists of 5 layers of filter material, namely seen from the inflow side to the downstream side of a layer of a thermoplastic material scrim, and a nonwoven fabric layer of loose, unconnected staple fibers another layer scrim, a meltblown layer and an outer layer spunbonded. With the exception of the areas of the marginal welds (which in FIG. 1 were removed to the still existing fold line F, as well as the welding of the flap K at the inlet opening E), the individual layers of the filter material are unconnected in the entire area. With this vacuum cleaner filter bag (in the closed state), the procedure for determining the immediately flown area X was performed. The vacuum cleaner filter bag was placed in a suitable vacuum cleaner and the vacuum cleaner was operated for five minutes at the highest power setting. For better visualization of the damage to the filter material, about 10 g of a mixture were added in portions from 10 g of mineral dust (AC Finedust) with 1 g of toner (black) sucked into the vacuum cleaner filter bag. However, the process may also be performed without the suction of dust and / or toner. Subsequently, the vacuum cleaner filter bag was removed from the vacuum cleaner and removed on three sides of the circumferential weld to assess the damage occurring. It can be seen that in a region X the loose fibers of the nonwoven fabric layer have been displaced. The darker inner circular section shown in region X represents a point at which less loose fibers are present, these were pressed concentrically to the side by the air flow entering through the inlet opening and thus blown away. Thus, the filter material is thinned in the interior of the region X, at the edge of the region X it is thickened by a bead of loose fibers. Both forms represent damage to the filter material, which must be avoided. In the other areas Y, which are outside the area X, no such damage could be found. In addition, it can be seen that, contrary to expectations, the region X in which damage occurs does not lie directly opposite the inlet opening E, but lies approximately diagonally opposite it. The directly impacted surface X, ie the region in which visually detectable damage due to the air flow of the filter material occurs, is determined as the region X, which represents the directly flowed-on region or the directly flowed-on surface. How out FIG. 1 can be seen, this area for the example of the flat bag on an irregular contour, which has an oval shape in a first approximation.

In FIG. 2 is a schematic section through the filter material of in FIG. 1 used vacuum cleaner filter bag, wherein FIG. 2a ) A section through the filter material prior to the inventive method for determining the directly flowed surface X and FIG. 2b ) make a cut along the in FIG. 1 represented line AB, ie according to the inventive method. In FIG. 2a ) the undamaged filter material is shown. It can be seen that the nonwoven fabric layer 2, which consists of loose, unconnected fiber, is enclosed by two layers of scrim 1 and 3 and thus fixed. However, instead of the scrim layers 1 and 3, other materials such as nonwoven fabrics, etc. may be used. It is also possible that one of the layers 1 and 3 is a netting, the Others a nonwoven fabric layer, etc. In addition, downstream of a meltblown layer 4 and a layer of spunbonded fabric 5 is arranged. The filter material, ie the sum of the layers 1, 2 and 3 in this case has a specific average thickness d, which can be determined according to EN ISO 9073-2: 1996, method B. To determine the directly flowed surface X is now the for FIG. 1 presented method in which air is blown into the vacuum cleaner filter bag for 5 minutes at the highest power setting of a vacuum cleaner. In the area in which the air flow occurs directly, that is to say unrestrained, onto the area X, there is a displacement or a blowing away of the loose, unconnected fibers; The fibers are thereby displaced to the side and accumulate in the edge region of the directly streamed surface X and it forms a free of fibers 6 space. In the middle of the directly flowed area X it comes to a thinning of the unconnected nonwoven fabric layer while in the Rim of this area an increased accumulation of loose fibers takes place, ie a thickening of this area occurs. However, both effects are disadvantageous for a permanent operation of the vacuum cleaner filter bag and thus for the service life: In the middle of the area X an increased permeability to dust occurs, while in the edge regions of the surface X due to the increased thickness d of the filter material an increased tendency Blockages of the filter material is given. The exact position of the directly flowed region X can be determined visually. Alternatively, the boundary of the region X can also be determined by determining the regions from which, starting from the remaining regions Y, there is an increase or decrease in the average layer thickness d of the filter material in the remaining regions. For this purpose, again the above-mentioned test standard for determining the layer thickness (EN ISO 9073-2: 1996, method B) can be used.

In FIG. 3 a vacuum cleaner filter bag according to the invention is shown which has bar-shaped weld seams S in the directly flown surface X as well as in an additional surface X 'which is arranged around the directly flown surface X. With the in FIG. 3 The vacuum cleaner filter bag shown was also the test method, which was also shown for the vacuum cleaner filter bag, performed. Also, this vacuum cleaner filter bag was placed in a vacuum cleaner and left for 5 minutes At the highest power setting of the vacuum cleaner air and for improved visualization of possible damage occurring about 10 g of a mixture of 10 g of mineral dust (AC Finedust) with 1 g of toner (black) sucked into the vacuum cleaner filter bag. The in FIG. 3 shown vacuum cleaner filter bag is made of the same filter material as the vacuum cleaner filter bag according to FIG. 1 formed and has the same dimensions or dimensions. In the vacuum cleaner filter bag according to the invention FIG. 3 were in the immediately flown area X, as for the vacuum cleaner filter bag in FIG. 1 determined, bar-shaped welded joints introduced in which all of the five layers of the filter material were connected. These welded joints are in FIG. 3 recognizable as black lines and marked with the reference symbol S. In addition, welds S have been introduced in an additional region X 'which is arranged around the region 34 which has flowed directly against it. It can be seen that solely by these welds S in the directly flowed region X and possibly also an additionally arranged around the area directly streamed X X 'introduced welds S are completely sufficient to the damage caused by the direct impact of the air or Particle flow on the directly impinged surface X occur (see Fig. 1 ), to prevent. The pressing surface portion of the welded joints S is in the example of the FIG. 3 about 0.7% both in the directly flowed area X and in the additional area X '. In the other areas of the vacuum cleaner filter bag (with the exception of the circumferential weld or the welded joint in the region of the inlet opening E for fixing the retaining plate K) no further welded joints of the individual layers of the filter material is introduced. According to the present invention, therefore, the number of welded joints or their pressing surface portion can be reduced to an absolutely necessary minimum, resulting in an extremely high life of the vacuum cleaner filter bag.

In FIG. 4 is an enlarged view of the back of the vacuum cleaner filter bag, as out FIG. 3 shown, shown. Shown are the individual welds S present in FIG. 4 are made visible through the white oval borders.

In FIG. 5 various possible welding patterns are shown, which may be introduced in the immediately flown region X or in an additional region X 'around the directly flowed region X. As in FIG. 5a ), a possible welded connection can be formed, for example, as a cross-shaped welded joint S, which is formed continuously by the directly flowed-on surface X and the additional region X '. Similarly, parallel welded joints S (see FIG. 5b ) to be possible. Further possible are cruciform welded joints ( FIG. 5c ), star-shaped welded joints ( FIG. 5d ) or bar-shaped welded joints ( FIG. 5e ). The decisive factor here is merely that the pressing surface portion of the welding pattern, ie the area through the weld or the sum of the surfaces of the individual welds based on the total area of the directly flowed area X and possibly the additional area X 'within the dimensions, such as defined in claim 1, lies.

A particularly preferred embodiment of a welding pattern is shown in FIG. 5f). This welding pattern is also the vacuum cleaner filter bag according to the invention, as in FIG. 3 or 4 was presented. The bar-shaped welds S lie on concentric circles, in addition, a bar-shaped weld in the center of the concentric circles is arranged.

In FIG. 6 is a sectional view along the line AB of FIG. 5f ). The filter material consists in this case again of the scrim layers 1 and 3 and the fiber fleece layer 2 and the meltblown layer 4 and the spunbonded nonwoven layer 5. In the area X there are respective bar-shaped welds S to which all the layers of the filter material 1 to 5 are connected. The welds are preferably introduced by means of an ultrasonic welding process. Also in the additional areas X 'welds may be present (see FIG. 5f ), these welds S are in FIG. 6 however, not shown by the selected section AB. The welds S present in the region of the directly impinged surface X, as well as possibly the additional surface X ', thereby give the filter material a sufficiently high intrinsic strength, so that it can be effectively prevented that the loose material is displaced during operation of the vacuum cleaner filter bag Fibers of the nonwoven fabric layer 2 takes place and thus damage (see also FIG. 1 ) can be effectively prevented.

Claims (22)

Filter bag for a vacuum cleaner,
comprising a bag of a filter material comprising at least three layers of filter material (1, 2, 3, 4, 5), of which at least one layer is a scrim (1, 3) and at least one layer is a nonwoven layer (2) containing staple fibers and / or or filaments, is
and an inlet opening (E) mounted in the bag,
wherein the filter material of the filter bag in at least one area (X), which makes up or make up a maximum of 20% of the through-flow surface of the filter bag, and optionally an additional area (X ') or additional areas, the or the Area (X) or each area (X) immediately surrounded, wherein the additional area (X ') or the additional areas a maximum of 80% of the area of the area (X) or each of the area (X) or make up , one or more joints (S), wherein the at least one nonwoven fabric layer (2) at least one of the at least two further layers scrim (1, 3) is connected, so that during operation of the filter bag, a permanent fixation of the staple fibers and / or Filaments of the fiber fleece layer (2) with the at least one of the at least two further layers Scrim (1, 3) is ensured
characterized,
that the pressing surface portion of the one or more joints (S) in this area (X) or in each of these areas and possibly the additional area (X ') and the additional areas of 0.1 and 40% and is greater than in the other areas (Y). Filter bag according to claim 1, characterized in that the region (X) or the regions in or into the air stream entering the interior of the filter bag through the inlet opening (E) is arranged directly flowed area or areas or are. Filter bag according to one of the preceding claims, characterized in that the pressing surface portion of the one or more connection points (S) in the area (X) or in each of the areas and possibly the additional area (X ') or the additional areas of 0.25 and 20%, more preferably from 0.5 to 10%. Filter bag according to one of the preceding claims, characterized in that the additional region (X ') or the additional regions 10 to 80%, preferably 20 to 70%, particularly preferably 30 to 60% of the area of the area (X) or respectively of the areas. Filter bag according to one of the preceding claims, characterized in that the additional region (X ') or the additional regions are circular or oval-shaped or the geometric shape of the region (X) or the areas corresponds or correspond. Filter bag according to one of the preceding claims, characterized in that in the other surfaces (Y) the at least one nonwoven fabric layer (2) is connected to at least one of the at least two further layers Scrim (1, 3), with the proviso that, based on the total flow-through surface of the filter bag in the other surfaces (Y) of the pressing surface portion of one or the sum of the plurality of joints (S) is a maximum of 5% of the permeable area of the filter bag in the remaining areas (Y) and an average of a maximum of 10 joints (S) per 10 cm ² are present, or at least one fiber fleece layer (2) with the other layers of scrim (1, 3) is unconnected. Filter bag according to one of the preceding claims, characterized in that in the region (X) or in the regions and optionally the additional area (X ') or the additional areas, the one or more joints (S) is bar-shaped, cross-shaped, star-shaped, punctiform, or linear and / or circular. Filter bag according to one of the preceding claims, that area (X) or in the areas and possibly the additional area (X ') or the additional areas a plurality of point or bar-shaped joints (S) are present, which are arranged on a plurality of concentric circles , Filter bag according to one of the preceding claims, characterized in that in the other surfaces (Y) on average at most 5, preferably at most 2, more preferably at most 1, further preferably at most 0.8, more preferably at most 0.6, in particular at most 0.3 Compounds per 10 cm ² are present and / or the pressing surface portion of the compounds in the remaining surfaces (Y) a maximum of 2%, preferably at most 1% of the surface area of the flow-through surface of the filter bag in the remaining areas (Y). Filter bag according to one of the preceding claims, characterized in that the scrim (1, 3) has a basis weight of 3 to 50 g / m ² . Filter bag according to one of the preceding claims, characterized in that the scrim (1, 3) is selected from the group consisting of Nettings, in particular woven, extruded or fibrillated Nettings, perforated films, weldable paper and nonwovens, especially wet-laid, dry-laid or extruded nonwovens. Filter bag according to one of the preceding claims, characterized in that the filter bag in the area (X) or the areas and optionally additionally in the area (X ') or in the additional areas no impact protection means and / or reinforcing inserts. Filter bag according to one of the preceding claims, characterized in that the connection point or the connection points (S) are welded joints, preferably ultrasonic welded joints or thermal welded joints, or adhesive joints, or by needling the nonwoven fabric layer (2) and at least one scrim layer (1, 3) is. Filter bag according to one of the preceding claims, characterized in that the filter material on the downstream side comprises at least one further material layer, preferably at least one meltblown layer (4) and / or a spunbonded layer (5). Filter bag according to one of the preceding claims, characterized in that in the region of the connection point or the connection points (S) all of the layers (1, 2, 3, 4, 5) of the filter material are connected. Filter bag according to one of the preceding claims, characterized in that the inlet opening (E) has a deflection device, via which the flow direction of the entering into the interior of the filter bag air flow is changed and / or has a closure flap (K) for the inlet opening. Filter bag according to one of the preceding claims, characterized in that the filter bag comprises at least one flow divider which divides the air flow entering through the inlet opening into the interior of the filter bag into at least two partial flows with different main flow direction, wherein the filter material in each immediately flown area (X) a respective partial flow and possibly additionally in a region (X '), which surrounds the respective directly flowed region (X), one or more connection points (S). Filter bag according to one of the preceding claims, characterized in that the filter bag a) is designed as a flat filter bag, which is formed by two circumferentially welded at the edges of material layers of the filter material, wherein the inlet opening (E) is mounted in a material layer, or b) is designed as a side filter bag, or c) is designed as a block bottom bag, wherein the inlet opening is mounted in the block bottom, or d) is designed as a pleated filter bag. Filter bag according to one of the preceding claims, characterized in that the staple fibers of the nonwoven fabric layer (2) have a length between 30 and 250 mm, preferably between 50 to 150 mm. Filter bag according to one of the preceding claims, characterized in that the inlet opening has a holding plate. Method for determining the area (X) or regions of the filter bag directly flown through by an air stream entering through the inlet opening (E) into the interior of a filter bag for a vacuum cleaner, in which a filter bag comprises
a filter material comprising at least three layers of filter material (1, 2, 3, 4, 5), of which at least one layer is a scrim (1, 3) and at least one layer is a nonwoven layer (2) containing staple fibers and / or filaments .
and an inlet opening in the bag,
is inserted into a vacuum cleaner suitable for the filter bag and air is sucked into the filter bag via the inlet opening for 5 minutes at the highest possible power setting of the vacuum cleaner,
and subsequently the region (s) which have visually detectable damage is defined as an area (X) directly impacted or areas directly affected by it. Method according to the preceding claim, characterized in that the at least one fibrous nonwoven layer (2) is connected to at least one of the at least two further layers Scrim (1, 3), with the proviso that, based on the entire throughflowable surface of the filter bag, the pressing surface portion of one or the sum of the plurality of connection points (S) a maximum of 5% of the flow-through surface of the filter bag and an average of at most 10 connection points (S) per 10 cm ² are present, or at least one nonwoven fabric layer (2) with the other layers Scrim (1, 3 ) is unconnected.

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